U.S. patent application number 17/411506 was filed with the patent office on 2021-12-09 for system and method for accelerated i/o access using storage array driver in off-the-shelf server.
The applicant listed for this patent is EMC IP Holding Company, LLC. Invention is credited to Robert DeCrescenzo, Jason J. Duquette, James Marriott Guyer, Steven T. McClure, Adnan Sahin, Michael Scharland.
Application Number | 20210382629 17/411506 |
Document ID | / |
Family ID | 1000005798789 |
Filed Date | 2021-12-09 |
United States Patent
Application |
20210382629 |
Kind Code |
A1 |
Sahin; Adnan ; et
al. |
December 9, 2021 |
System and Method for Accelerated I/O Access Using Storage Array
Driver in Off-The-Shelf Server
Abstract
A method, computer program product, and computer system for
receiving, by a computing device, an I/O request. It may be
identified whether the I/O request is eligible for handling via a
first path without also requiring handling via a second path. If
the I/O request is eligible, the I/O request may be processed via
the first path on a host I/O stack without processing the I/O
request via the second path on a storage array I/O stack. If the
I/O request is ineligible, the I/O request may be processed via the
first path on the host
Inventors: |
Sahin; Adnan; (Needham,
MA) ; Scharland; Michael; (Franklin, MA) ;
DeCrescenzo; Robert; (Franklin, MA) ; McClure; Steven
T.; (Northborough, MA) ; Guyer; James Marriott;
(Northborough, MA) ; Duquette; Jason J.; (Milford,
MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EMC IP Holding Company, LLC |
Hopkinton |
MA |
US |
|
|
Family ID: |
1000005798789 |
Appl. No.: |
17/411506 |
Filed: |
August 25, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15799571 |
Oct 31, 2017 |
11106360 |
|
|
17411506 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 3/0607 20130101;
G06F 3/0635 20130101; G06F 3/0608 20130101; G06F 3/0665 20130101;
G06F 3/0611 20130101; G06F 3/0689 20130101; G06F 3/0614
20130101 |
International
Class: |
G06F 3/06 20060101
G06F003/06 |
Claims
1. A computer-implemented method comprising: receiving, by a
computing device, an I/O request; identifying a first path for
processing I/O requests, wherein the first path includes processing
by a general purpose processor; identifying a second path for
processing I/O requests, wherein the second path includes
processing by a special purpose storage processor; identifying
whether the I/O request is eligible for handling via a first path
without also requiring handling via a second path; if the I/O
request is eligible, processing the I/O request via the first path
on a host I/O stack without processing the I/O request via the
second path on a storage array I/O stack; and if the I/O request is
ineligible, processing the I/O request via the first path on the
host I/O stack and via the second path on the storage array I/O
stack, wherein an ineligible I/O request includes at least one of a
control command and an I/O request satisfying a predetermined
condition, wherein satisfying the predetermined condition includes
a Server Device Handling layer in the host I/O stack configured to
determine, in coordination with the storage array I/O stack,
whether the control command should be passed to the storage array
I/O stack via the second path.
2. The computer-implemented method of claim 1 wherein an eligible
I/O request includes one of a data read request and a data write
request.
3. The computer-implemented method of claim 1 further comprising
processing the I/O request via the first path on the host I/O stack
and via the second path on the storage array I/O stack when
processing of the I/O request via the host I/O stack on the first
path without processing the I/O request via the second path on the
storage array I/O stack fails.
4. The computer-implemented method of claim 1 further comprising
returning a completion status to an application layer of the host
I/O stack when processing of the I/O request via the host I/O stack
on the first path without processing the I/O request via the second
path on the storage array I/O stack successfully completes.
5. The computer-implemented method of claim 1 wherein the internal
fabric request resulting from the metadata query includes
requesting at least one of a location status and a cache status of
metadata within the storage array I/O stack.
6. A computer program product residing on a non-transitory computer
readable storage medium having a plurality of instructions stored
thereon which, when executed across one or more processors, causes
at least a portion of the one or more processors to perform
operations comprising: receiving an I/O request; identifying a
first path for processing I/O requests, wherein the first path
includes processing by a general purpose processor; identifying a
second path for processing I/O requests, wherein the second path
includes processing by a special purpose storage processor;
identifying whether the I/O request is eligible for handling via a
first path without also requiring handling via a second path; if
the I/O request is eligible, processing the I/O request via the
first path on a host I/O stack without processing the I/O request
via the second path on a storage array I/O stack; and if the I/O
request is ineligible, processing the I/O request via the first
path on the host I/O stack and via the second path on the storage
array I/O stack, wherein an ineligible I/O request includes at
least one of a control command and an I/O request satisfying a
predetermined condition, wherein satisfying the predetermined
condition includes a Server Device Handling layer in the host I/O
stack configured to determine, in coordination with the storage
array I/O stack, whether the control command should be passed to
the storage array I/O stack via the second path.
7. The computer program product of claim 6 wherein an eligible I/O
request includes one of a data read request and a data write
request.
8. The computer program product of claim 6 wherein the operations
further comprise processing the I/O request via the first path on
the host I/O stack and via the second path on the storage array I/O
stack when processing of the I/O request via the host I/O stack on
the first path without processing the I/O request via the second
path on the storage array I/O stack fails.
9. The computer program product of claim 6 wherein the operations
further comprise returning a completion status to an application
layer of the host I/O stack when processing of the I/O request via
the host I/O stack on the first path without processing the I/O
request via the second path on the storage array I/O stack
successfully completes.
10. The computer program product of claim 6 wherein the internal
fabric request resulting from the metadata query includes
requesting at least one of a location status and a cache status of
metadata within the storage array I/O stack.
11. A computing system including one or more processors and one or
more memories configured to perform operations comprising:
receiving an I/O request; identifying a first path for processing
I/O requests, wherein the first path includes processing by a
general purpose processor; identifying a second path for processing
I/O requests, wherein the second path includes processing by a
special purpose storage processor; identifying whether the I/O
request is eligible for handling via a first path without also
requiring handling via a second path; if the I/O request is
eligible, processing the I/O request via the first path on a host
I/O stack without processing the I/O request via the second path on
a storage array I/O stack; and if the I/O request is ineligible,
processing the I/O request via the first path on the host I/O stack
and via the second path on the storage array I/O stack, wherein an
ineligible I/O request includes at least one of a control command
and an I/O request satisfying a predetermined condition, wherein
satisfying the predetermined condition includes a Server Device
Handling layer in the host I/O stack configured to determine, in
coordination with the storage array I/O stack, whether the control
command should be passed to the storage array I/O stack via the
second path.
12. The computing system of claim 11 wherein an eligible I/O
request includes one of a data read request and a data write
request.
13. The computing system of claim 11 wherein the operations further
comprise processing the I/O request via the first path on the host
I/O stack and via the second path on the storage array I/O stack
when processing of the I/O request via the host I/O stack on the
first path without processing the I/O request via the second path
on the storage array I/O stack fails, and returning a completion
status to an application layer of the host I/O stack when
processing of the I/O request via the host I/O stack on the first
path without processing the I/O request via the second path on the
storage array I/O stack successfully completes.
14. The computing system of claim 11 wherein the internal fabric
request resulting from the metadata query includes requesting at
least one of a location status and a cache status of metadata
within the storage array I/O stack.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The subject application is a continuation of U.S.
application Ser. No. No. 15/799,571; filed Oct. 31, 2017. The
entire disclosure of which is herein incorporated by reference.
BACKGROUND
[0002] Generally, with the increasing amounts of information being
stored, it may be beneficial to efficiently store and manage that
information. While there may be numerous techniques for storing and
managing information, each technique may have tradeoffs between
reliability and efficiency.
BRIEF SUMMARY OF DISCLOSURE
[0003] In one example implementation, a method, performed by one or
more computing devices, may include but is not limited to
receiving, by a computing device, an I/O request. It may be
identified whether the I/O request is eligible for handling via a
first path without also requiring handling via a second path. If
the I/O request is eligible, the I/O request may be processed via
the first path on a host I/O stack without processing the I/O
request via the second path on a storage array I/O stack. If the
I/O request is ineligible, the I/O request may be processed via the
first path on the host I/O stack and via the second path on the
storage array I/O stack.
[0004] One or more of the following example features may be
included. An eligible I/O request may include one of a data read
request and a data write request. An ineligible I/O request may
include at least one of a control command and an I/O request
satisfying a predetermined condition. Processing the I/O request
via the first path on the host I/O stack without processing the I/O
request via the second path on the storage array I/O stack may
include processing an optimistic query. Processing the I/O request
via the first path on the host I/O stack without processing the I/O
request via the second path on the storage array I/O stack may
include generating a metadata query based upon, at least in part,
the I/O request. The I/O request may be processed via the first
path on the host I/O stack and via the second path on the storage
array I/O stack when processing of the I/O request via the host I/O
stack on the first path without processing the I/O request via the
second path on the storage array I/O stack fails. A completion
status may be returned to an application layer of the host I/O
stack when processing of the I/O request via the host I/O stack on
the first path without processing the I/O request via the second
path on the storage array I/O stack successfully completes.
[0005] In another example implementation, a computing system may
include one or more processors and one or more memories configured
to perform operations that may include but are not limited to
receiving an I/O request. It may be identified whether the I/O
request is eligible for handling via a first path without also
requiring handling via a second path. If the I/O request is
eligible, the I/O request may be processed via the first path on a
host I/O stack without processing the I/O request via the second
path on a storage array I/O stack. If the I/O request is
ineligible, the I/O request may be processed via the first path on
the host I/O stack and via the second path on the storage array I/O
stack.
[0006] One or more of the following example features may be
included. An eligible I/O request may include one of a data read
request and a data write request. An ineligible I/O request may
include at least one of a control command and an I/O request
satisfying a predetermined condition. Processing the I/O request
via the first path on the host I/O stack without processing the I/O
request via the second path on the storage array I/O stack may
include processing an optimistic query. Processing the I/O request
via the first path on the host I/O stack without processing the I/O
request via the second path on the storage array I/O stack may
include generating a metadata query based upon, at least in part,
the I/O request. The I/O request may be processed via the first
path on the host I/O stack and via the second path on the storage
array I/O stack when processing of the I/O request via the host I/O
stack on the first path without processing the I/O request via the
second path on the storage array I/O stack fails. A completion
status may be returned to an application layer of the host I/O
stack when processing of the I/O request via the host I/O stack on
the first path without processing the I/O request via the second
path on the storage array I/O stack successfully completes.
[0007] In another example implementation, a computer program
product may reside on a computer readable storage medium having a
plurality of instructions stored thereon which, when executed
across one or more processors, may cause at least a portion of the
one or more processors to perform operations that may include but
are not limited to receiving an I/O request. It may be identified
whether the I/O request is eligible for handling via a first path
without also requiring handling via a second path. If the I/O
request is eligible, the I/O request may be processed via the first
path on a host I/O stack without processing the I/O request via the
second path on a storage array I/O stack. If the I/O request is
ineligible, the I/O request may be processed via the first path on
the host I/O stack and via the second path on the storage array I/O
stack.
[0008] One or more of the following example features may be
included. An eligible I/O request may include one of a data read
request and a data write request. An ineligible I/O request may
include at least one of a control command and an I/O request
satisfying a predetermined condition. Processing the I/O request
via the first path on the host I/O stack without processing the I/O
request via the second path on the storage array I/O stack may
include processing an optimistic query. Processing the I/O request
via the first path on the host I/O stack without processing the I/O
request via the second path on the storage array I/O stack may
include generating a metadata query based upon, at least in part,
the I/O request. The I/O request may be processed via the first
path on the host I/O stack and via the second path on the storage
array I/O stack when processing of the I/O request via the host I/O
stack on the first path without processing the I/O request via the
second path on the storage array I/O stack fails. A completion
status may be returned to an application layer of the host I/O
stack when processing of the I/O request via the host I/O stack on
the first path without processing the I/O request via the second
path on the storage array I/O stack successfully completes.
[0009] The details of one or more example implementations are set
forth in the accompanying drawings and the description below. Other
possible example features and/or possible example advantages will
become apparent from the description, the drawings, and the claims.
Some implementations may not have those possible example features
and/or possible example advantages, and such possible example
features and/or possible example advantages may not necessarily be
required of some implementations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an example diagrammatic view of an Off-the-shelf
(OTS) process coupled to an example distributed computing network
according to one or more example implementations of the
disclosure;
[0011] FIG. 2 is an example diagrammatic view of a computer of FIG.
1 according to one or more example implementations of the
disclosure;
[0012] FIG. 3 is an example diagrammatic view of a storage target
of FIG. 1 according to one or more example implementations of the
disclosure;
[0013] FIG. 4 is an example diagrammatic view of an example SAN
Model according to one or more example implementations of the
disclosure;
[0014] FIG. 5 is an example diagrammatic view of an example SAN
Model according to one or more example implementations of the
disclosure;
[0015] FIG. 6 is an example flowchart of a OTS process according to
one or more example implementations of the disclosure;
[0016] FIG. 7 is an example diagrammatic view of an example
off-the-shelf model according to one or more example
implementations of the disclosure;
[0017] FIG. 8 is an example diagrammatic view of an example
off-the-shelf model according to one or more example
implementations of the disclosure; and
[0018] FIG. 9 is an example diagrammatic view of an example storage
system layout according to one or more example implementations of
the disclosure.
[0019] Like reference symbols in the various drawings indicate like
elements.
DETAILED DESCRIPTION
System Overview
[0020] In some implementations, the present disclosure may be
embodied as a method, system, or computer program product.
Accordingly, in some implementations, the present disclosure may
take the form of an entirely hardware implementation, an entirely
software implementation (including firmware, resident software,
micro-code, etc.) or an implementation combining software and
hardware aspects that may all generally be referred to herein as a
"circuit," "module" or "system." Furthermore, in some
implementations, the present disclosure may take the form of a
computer program product on a computer-usable storage medium having
computer-usable program code embodied in the medium.
[0021] In some implementations, any suitable computer usable or
computer readable medium (or media) may be utilized. The computer
readable medium may be a computer readable signal medium or a
computer readable storage medium. The computer-usable, or
computer-readable, storage medium (including a storage device
associated with a computing device or client electronic device) may
be, for example, but is not limited to, an electronic, magnetic,
optical, electromagnetic, infrared, or semiconductor system,
apparatus, device, or any suitable combination of the foregoing.
More specific examples (a non-exhaustive list) of the
computer-readable medium may include the following: an electrical
connection having one or more wires, a portable computer diskette,
a hard disk, a random access memory (RAM), a read-only memory
(ROM), an erasable programmable read-only memory (EPROM or Flash
memory), an optical fiber, a portable compact disc read-only memory
(CD-ROM), an optical storage device, a digital versatile disk
(DVD), a static random access memory (SRAM), a memory stick, a
floppy disk, a mechanically encoded device such as punch-cards or
raised structures in a groove having instructions recorded thereon,
a media such as those supporting the internet or an intranet, or a
magnetic storage device. Note that the computer-usable or
computer-readable medium could even be a suitable medium upon which
the program is stored, scanned, compiled, interpreted, or otherwise
processed in a suitable manner, if necessary, and then stored in a
computer memory. In the context of the present disclosure, a
computer-usable or computer-readable, storage medium may be any
tangible medium that can contain or store a program for use by or
in connection with the instruction execution system, apparatus, or
device.
[0022] In some implementations, a computer readable signal medium
may include a propagated data signal with computer readable program
code embodied therein, for example, in baseband or as part of a
carrier wave. In some implementations, such a propagated signal may
take any of a variety of forms, including, but not limited to,
electro-magnetic, optical, or any suitable combination thereof. In
some implementations, the computer readable program code may be
transmitted using any appropriate medium, including but not limited
to the internet, wireline, optical fiber cable, RF, etc. In some
implementations, a computer readable signal medium may be any
computer readable medium that is not a computer readable storage
medium and that can communicate, propagate, or transport a program
for use by or in connection with an instruction execution system,
apparatus, or device.
[0023] In some implementations, computer program code for carrying
out operations of the present disclosure may be assembler
instructions, instruction-set-architecture (ISA) instructions,
machine instructions, machine dependent instructions, microcode,
firmware instructions, state-setting data, or either source code or
object code written in any combination of one or more programming
languages, including an object oriented programming language such
as Java.RTM., Smalltalk, C++ or the like. Java.RTM. and all
Java-based trademarks and logos are trademarks or registered
trademarks of Oracle and/or its affiliates. However, the computer
program code for carrying out operations of the present disclosure
may also be written in conventional procedural programming
languages, such as the "C" programming language, PASCAL, or similar
programming languages, as well as in scripting languages such as
Javascript, PERL, or Python. The program code may execute entirely
on the user's computer, partly on the user's computer, as a
stand-alone software package, partly on the user's computer and
partly on a remote computer or entirely on the remote computer or
server. In the latter scenario, the remote computer may be
connected to the user's computer through a local area network (LAN)
or a wide area network (WAN), or the connection may be made to an
external computer (for example, through the internet using an
Internet Service Provider). In some implementations, electronic
circuitry including, for example, programmable logic circuitry,
field-programmable gate arrays (FPGAs) or other hardware
accelerators, micro-controller units (MCUs), or programmable logic
arrays (PLAs) may execute the computer readable program
instructions/code by utilizing state information of the computer
readable program instructions to personalize the electronic
circuitry, in order to perform aspects of the present
disclosure.
[0024] In some implementations, the flowchart and block diagrams in
the figures illustrate the architecture, functionality, and
operation of possible implementations of apparatus (systems),
methods and computer program products according to various
implementations of the present disclosure. Each block in the
flowchart and/or block diagrams, and combinations of blocks in the
flowchart and/or block diagrams, may represent a module, segment,
or portion of code, which comprises one or more executable computer
program instructions for implementing the specified logical
function(s)/act(s). These computer program instructions may be
provided to a processor of a general purpose computer, special
purpose computer, or other programmable data processing apparatus
to produce a machine, such that the computer program instructions,
which may execute via the processor of the computer or other
programmable data processing apparatus, create the ability to
implement one or more of the functions/acts specified in the
flowchart and/or block diagram block or blocks or combinations
thereof. It should be noted that, in some implementations, the
functions noted in the block(s) may occur out of the order noted in
the figures. For example, two blocks shown in succession may, in
fact, be executed substantially concurrently, or the blocks may
sometimes be executed in the reverse order, depending upon the
functionality involved.
[0025] In some implementations, these computer program instructions
may also be stored in a computer-readable memory that can direct a
computer or other programmable data processing apparatus to
function in a particular manner, such that the instructions stored
in the computer-readable memory produce an article of manufacture
including instruction means which implement the function/act
specified in the flowchart and/or block diagram block or blocks or
combinations thereof.
[0026] In some implementations, the computer program instructions
may also be loaded onto a computer or other programmable data
processing apparatus to cause a series of operational steps to be
performed (not necessarily in a particular order) on the computer
or other programmable apparatus to produce a computer implemented
process such that the instructions which execute on the computer or
other programmable apparatus provide steps for implementing the
functions/acts (not necessarily in a particular order) specified in
the flowchart and/or block diagram block or blocks or combinations
thereof.
[0027] Referring now to the example implementation of FIG. 1, there
is shown off-the-shelf (OTS) process 10 that may reside on and may
be executed by a computer (e.g., computer 12), which may be
connected to a network (e.g., network 14) (e.g., the internet or a
local area network). Examples of computer 12 (and/or one or more of
the client electronic devices noted below) may include, but are not
limited to, a storage system (e.g., a Network Attached Storage
(NAS) system, a Storage Area Network (SAN)), a personal
computer(s), a laptop computer(s), mobile computing device(s), a
server computer, a series of server computers, a mainframe
computer(s), or a computing cloud(s). As is known in the art, a SAN
may include one or more of the client electronic devices, including
a RAID device and a NAS system. In some implementations, each of
the aforementioned may be generally described as a computing
device. In certain implementations, a computing device may be a
physical or virtual device. In many implementations, a computing
device may be any device capable of performing operations, such as
a dedicated processor, a portion of a processor, a virtual
processor, a portion of a virtual processor, portion of a virtual
device, or a virtual device. In some implementations, a processor
may be a physical processor or a virtual processor. In some
implementations, a virtual processor may correspond to one or more
parts of one or more physical processors. In some implementations,
the instructions/logic may be distributed and executed across one
or more processors, virtual or physical, to execute the
instructions/logic. Computer 12 may execute an operating system,
for example, but not limited to, Microsoft.RTM. Windows.RTM.;
Mac.RTM. OS X.RTM.; Red Hat.RTM. Linux.RTM., Windows.RTM. Mobile,
Chrome OS, Blackberry OS, Fire OS, or a custom operating system.
(Microsoft and Windows are registered trademarks of Microsoft
Corporation in the United States, other countries or both; Mac and
OS X are registered trademarks of Apple Inc. in the United States,
other countries or both; Red Hat is a registered trademark of Red
Hat Corporation in the United States, other countries or both; and
Linux is a registered trademark of Linus Torvalds in the United
States, other countries or both).
[0028] In some implementations, as will be discussed below in
greater detail, a OTS process, such as OTS process 10 of FIG. 1,
may receive, by a computing device, an I/O request (e.g., I/O 15).
It may be identified whether the I/O request is eligible for
handling via a first path without also requiring handling via a
second path. If the I/O request is eligible, the I/O request may be
processed via the first path on a host I/O stack without processing
the I/O request via the second path on a storage array I/O stack.
If the I/O request is ineligible, the I/O request may be processed
via the first path on the host I/O stack and via the second path on
the storage array I/O stack.
[0029] In some implementations, the instruction sets and
subroutines of OTS process 10, which may be stored on storage
device, such as storage device 16, coupled to computer 12, may be
executed by one or more processors and one or more memory
architectures included within computer 12. In some implementations,
storage device 16 may include but is not limited to: a hard disk
drive; all forms of flash memory storage devices; a tape drive; an
optical drive; a RAID array (or other array); a random access
memory (RAM); a read-only memory (ROM); or combination thereof. In
some implementations, storage device 16 may be organized as an
extent, an extent pool, a RAID extent (e.g., an example 4D+1P R5,
where the RAID extent may include, e.g., five storage device
extents that may be allocated from, e.g., five different storage
devices), a mapped RAID (e.g., a collection of RAID extents), or
combination thereof.
[0030] In some implementations, network 14 may be connected to one
or more secondary networks (e.g., network 18), examples of which
may include but are not limited to: a local area network; a wide
area network; or an intranet, for example.
[0031] In some implementations, computer 12 may include a data
store, such as a database (e.g., relational database,
object-oriented database, triplestore database, etc.) and may be
located within any suitable memory location, such as storage device
16 coupled to computer 12. In some implementations, data, metadata,
information, etc. described throughout the present disclosure may
be stored in the data store. In some implementations, computer 12
may utilize any known database management system such as, but not
limited to, DB2, in order to provide multi-user access to one or
more databases, such as the above noted relational database. In
some implementations, the data store may also be a custom database,
such as, for example, a flat file database or an XML database. In
some implementations, any other form(s) of a data storage structure
and/or organization may also be used. In some implementations, OTS
process 10 may be a component of the data store, a standalone
application that interfaces with the above noted data store and/or
an applet/application that is accessed via client applications 22,
24, 26, 28. In some implementations, the above noted data store may
be, in whole or in part, distributed in a cloud computing topology.
In this way, computer 12 and storage device 16 may refer to
multiple devices, which may also be distributed throughout the
network. An example cloud computing environment that may be used
with the disclosure may include but is not limited to, e.g.,
Elastic Cloud Storage.TM. from Dell EMC.TM. of Hopkinton, Mass. In
some implementations, other cloud computing environments may be
used without departing from the scope of the disclosure.
[0032] In some implementations, computer 12 may execute a storage
management application (e.g., storage management application 21),
examples of which may include, but are not limited to, e.g., a
storage system application, a cloud computing application, a data
synchronization application, a data migration application, a
garbage collection application, or other application that allows
for the implementation and/or management of data in a clustered (or
non-clustered) environment (or the like). In some implementations,
OTS process 10 and/or storage management application 21 may be
accessed via one or more of client applications 22, 24, 26, 28. In
some implementations, OTS process 10 may be a standalone
application, or may be an applet/application/script/extension that
may interact with and/or be executed within storage management
application 21, a component of storage management application 21,
and/or one or more of client applications 22, 24, 26, 28. In some
implementations, storage management application 21 may be a
standalone application, or may be an
applet/application/script/extension that may interact with and/or
be executed within OTS process 10, a component of OTS process 10,
and/or one or more of client applications 22, 24, 26, 28. In some
implementations, one or more of client applications 22, 24, 26, 28
may be a standalone application, or may be an
applet/application/script/extension that may interact with and/or
be executed within and/or be a component of OTS process 10 and/or
storage management application 21. Examples of client applications
22, 24, 26, 28 may include, but are not limited to, e.g., a storage
system application, a cloud computing application, a data
synchronization application, a data migration application, a
garbage collection application, or other application that allows
for the implementation and/or management of data in a clustered (or
non-clustered) environment (or the like), a standard and/or mobile
web browser, an email application (e.g., an email client
application), a textual and/or a graphical user interface, a
customized web browser, a plugin, an Application Programming
Interface (API), or a custom application. The instruction sets and
subroutines of client applications 22, 24, 26, 28, which may be
stored on storage devices 30, 32, 34, 36, coupled to client
electronic devices 38, 40, 42, 44, may be executed by one or more
processors and one or more memory architectures incorporated into
client electronic devices 38, 40, 42, 44.
[0033] In some implementations, one or more of storage devices 30,
32, 34, 36, may include but are not limited to: hard disk drives;
flash drives, tape drives; optical drives; RAID arrays; random
access memories (RAM); and read-only memories (ROM). Examples of
client electronic devices 38, 40, 42, 44 (and/or computer 12) may
include, but are not limited to, a personal computer (e.g., client
electronic device 38), a laptop computer (e.g., client electronic
device 40), a smart/data-enabled, cellular phone (e.g., client
electronic device 42), a notebook computer (e.g., client electronic
device 44), a tablet, a server, a television, a smart television, a
media (e.g., video, photo, etc.) capturing device, and a dedicated
network device. Client electronic devices 38, 40, 42, 44 may each
execute an operating system, examples of which may include but are
not limited to, Android.TM., Apple.RTM. iOS.RTM., Mac.RTM. OS
X.RTM.; Red Hat.RTM. Linux.RTM., Windows.RTM. Mobile, Chrome OS,
Blackberry OS, Fire OS, or a custom operating system.
[0034] In some implementations, one or more of client applications
22, 24, 26, 28 may be configured to effectuate some or all of the
functionality of OTS process 10 (and vice versa). Accordingly, in
some implementations, OTS process 10 may be a purely server-side
application, a purely client-side application, or a hybrid
server-side/client-side application that is cooperatively executed
by one or more of client applications 22, 24, 26, 28 and/or OTS
process 10.
[0035] In some implementations, one or more of client applications
22, 24, 26, 28 may be configured to effectuate some or all of the
functionality of storage management application 21 (and vice
versa). Accordingly, in some implementations, storage management
application 21 may be a purely server-side application, a purely
client-side application, or a hybrid server-side/client-side
application that is cooperatively executed by one or more of client
applications 22, 24, 26, 28 and/or storage management application
21. As one or more of client applications 22, 24, 26, 28, OTS
process 10, and storage management application 21, taken singly or
in any combination, may effectuate some or all of the same
functionality, any description of effectuating such functionality
via one or more of client applications 22, 24, 26, 28, OTS process
10, storage management application 21, or combination thereof, and
any described interaction(s) between one or more of client
applications 22, 24, 26, 28, OTS process 10, storage management
application 21, or combination thereof to effectuate such
functionality, should be taken as an example only and not to limit
the scope of the disclosure.
[0036] In some implementations, one or more of users 46, 48, 50, 52
may access computer 12 and OTS process 10 (e.g., using one or more
of client electronic devices 38, 40, 42, 44) directly through
network 14 or through secondary network 18. Further, computer 12
may be connected to network 14 through secondary network 18, as
illustrated with phantom link line 54. OTS process 10 may include
one or more user interfaces, such as browsers and textual or
graphical user interfaces, through which users 46, 48, 50, 52 may
access OTS process 10.
[0037] In some implementations, the various client electronic
devices may be directly or indirectly coupled to network 14 (or
network 18). For example, client electronic device 38 is shown
directly coupled to network 14 via a hardwired network connection.
Further, client electronic device 44 is shown directly coupled to
network 18 via a hardwired network connection. Client electronic
device 40 is shown wirelessly coupled to network 14 via wireless
communication channel 56 established between client electronic
device 40 and wireless access point (i.e., WAP) 58, which is shown
directly coupled to network 14. WAP 58 may be, for example, an IEEE
802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, Wi-Fi.RTM., RFID,
and/or Bluetooth.TM. (including Bluetooth.TM. Low Energy) device
that is capable of establishing wireless communication channel 56
between client electronic device 40 and WAP 58. Client electronic
device 42 is shown wirelessly coupled to network 14 via wireless
communication channel 60 established between client electronic
device 42 and cellular network/bridge 62, which is shown by example
directly coupled to network 14.
[0038] In some implementations, some or all of the IEEE 802.11x
specifications may use Ethernet protocol and carrier sense multiple
access with collision avoidance (i.e., CSMA/CA) for path sharing.
The various 802.11x specifications may use phase-shift keying
(i.e., PSK) modulation or complementary code keying (i.e., CCK)
modulation, for example. Bluetooth.TM. (including Bluetooth.TM. Low
Energy) is a telecommunications industry specification that allows,
e.g., mobile phones, computers, smart phones, and other electronic
devices to be interconnected using a short-range wireless
connection. Other forms of interconnection (e.g., Near Field
Communication (NFC)) may also be used.
[0039] In some implementations, various I/O requests (e.g., I/O
request 15) may be sent from, e.g., client applications 22, 24, 26,
28 to, e.g., computer 12. Examples of I/O request 15 may include
but are not limited to, data write requests (e.g., a request that
content be written to computer 12) and data read requests (e.g., a
request that content be read from computer 12).
Data Storage System
[0040] Referring also to the example implementation of FIGS. 2-3
(e.g., where computer 12 may be configured as a data storage
system), computer 12 may include storage processor 100 (which may
instead be a general purpose processor) and a plurality of storage
targets (e.g., storage targets 102, 104, 106, 108, 110). In some
implementations, storage targets 102, 104, 106, 108, 110 may
include any of the above-noted storage devices. In some
implementations, storage targets 102, 104, 106, 108, 110 may be
configured to provide various levels of performance and/or high
availability. For example, storage targets 102, 104, 106, 108, 110
may be configured to form a non-fully-duplicative fault-tolerant
data storage system (such as a non-fully-duplicative RAID data
storage system), examples of which may include but are not limited
to: RAID 3 arrays, RAID 4 arrays, RAID 5 arrays, and/or RAID 6
arrays. It will be appreciated that various other types of RAID
arrays may be used without departing from the scope of the present
disclosure.
[0041] While in this particular example, computer 12 is shown to
include five storage targets (e.g., storage targets 102, 104, 106,
108, 110), this is for example purposes only and is not intended
limit the present disclosure. For instance, the actual number of
storage targets may be increased or decreased depending upon, e.g.,
the level of redundancy/performance/capacity required.
[0042] Further, the storage targets (e.g., storage targets 102,
104, 106, 108, 110) included with computer 12 may be configured to
form a plurality of discrete storage arrays. For instance, and
assuming for example purposes only that computer 12 includes, e.g.,
ten discrete storage targets, a first five targets (of the ten
storage targets) may be configured to form a first RAID array and a
second five targets (of the ten storage targets) may be configured
to form a second RAID array.
[0043] In some implementations, one or more of storage targets 102,
104, 106, 108, 110 may be configured to store coded data (e.g., via
storage management application 21), wherein such coded data may
allow for the regeneration of data lost/corrupted on one or more of
storage targets 102, 104, 106, 108, 110. Examples of such coded
data may include but is not limited to parity data and Reed-Solomon
data. Such coded data may be distributed across all of storage
targets 102, 104, 106, 108, 110 or may be stored within a specific
storage target.
[0044] Examples of storage targets 102, 104, 106, 108, 110 may
include one or more data arrays, wherein a combination of storage
targets 102, 104, 106, 108, 110 (and any processing/control systems
associated with storage management application 21) may form data
array 112.
[0045] The manner in which computer 12 is implemented may vary
depending upon e.g., the level of redundancy/performance/capacity
required. For example, computer 12 may be configured as a SAN
(i.e., a Storage Area Network), in which storage processor 100 may
be, e.g., a dedicated computing system and each of storage targets
102, 104, 106, 108, 110 may be a RAID device.
[0046] In the example where computer 12 is configured as a SAN, the
various components of computer 12 (e.g., storage processor 100, and
storage targets 102, 104, 106, 108, 110) may be coupled using
network infrastructure 114, examples of which may include but are
not limited to an Ethernet (e.g., Layer 2 or Layer 3) network, a
fiber channel network, an InfiniBand network, or any other circuit
switched/packet switched network.
[0047] As discussed above, various I/O requests (e.g., I/O request
15) may be generated. For example, these I/O requests may be sent
from, e.g., client applications 22, 24, 26, 28 to, e.g., computer
12. Additionally/alternatively, I/O requests may be generated by
computer 12, where the generated I/Os may be due to processing
requests from, e.g., client applications 22, 24, 26, 28.
Additionally/alternatively (e.g., when storage processor 100 is
configured as an application server or otherwise), these I/O
requests may be internally generated within storage processor 100
(e.g., via a server application, such as server application 23).
Examples of I/O request 15 may include but are not limited to data
write request 116 (e.g., a request that content 118 be written to
computer 12) and data read request 120 (e.g., a request that
content 118 be read from computer 12).
[0048] In some implementations, during operation of storage
processor 100, content 118 to be written to computer 12 may be
received and/or processed by storage processor 100 (e.g., via
storage management application 21). Additionally/alternatively
(e.g., when storage processor 100 is configured as an application
server or otherwise), content 118 to be written to computer 12 may
be internally generated by storage processor 100 (e.g., via server
application 23).
[0049] As discussed above, the instruction sets and subroutines of
storage management application 21, which may be stored on storage
device 16 included within computer 12, may be executed by one or
more processors and one or more memory architectures included with
computer 12. Accordingly, in addition to being executed on storage
processor 100, some or all of the instruction sets and subroutines
of storage management application 21 (and/or OTS process 10) may be
executed by one or more processors and one or more memory
architectures included with data array 112.
[0050] In some implementations, storage processor 100 may include
front end cache memory system 122 (e.g., host-based cache memory).
Examples of front end cache memory system 122 may include but are
not limited to a volatile, solid-state, cache memory system (e.g.,
a dynamic RAM cache memory system), a non-volatile, solid-state,
cache memory system (e.g., a flash-based, cache memory system),
and/or any of the above-noted storage devices.
[0051] In some implementations, storage processor 100 may initially
store content 118 within front end cache memory system 122.
Depending upon the manner in which front end cache memory system
122 is configured, storage processor 100 (e.g., via storage
management application 21) may immediately write content 118 to
data array 112 (e.g., if front end cache memory system 122 is
configured as a write-through cache) or may subsequently write
content 118 to data array 112 (e.g., if front end cache memory
system 122 is configured as a write-back cache).
[0052] In some implementations, one or more of storage targets 102,
104, 106, 108, 110 may include a backend cache memory system.
Examples of the backend cache memory system (e.g., array-based
cache memory) may include but are not limited to a volatile,
solid-state, cache memory system (e.g., a dynamic RAM cache memory
system), a non-volatile, solid-state, cache memory system (e.g., a
flash-based, cache memory system), and/or any of the above-noted
storage devices.
Storage Targets
[0053] As discussed above, one or more of storage targets 102, 104,
106, 108, 110 may be a RAID device. For instance, and referring
also to FIG. 3, there is shown example target 150, wherein target
150 may be one example implementation of a RAID implementation of,
e.g., storage target 102, storage target 104, storage target 106,
storage target 108, and/or storage target 110. Examples of storage
devices 154, 156, 158, 160, 162 may include one or more
electro-mechanical hard disk drives, one or more solid-state/flash
devices, and/or any of the above-noted storage devices. It will be
appreciated that while the term "disk" or "drive" may be used
throughout, these may refer to and be used interchangeably with any
types of appropriate storage devices as the context and
functionality of the storage device permits.
[0054] In some implementations, target 150 may include storage
processor 152 and a plurality of storage devices (e.g., storage
devices 154, 156, 158, 160, 162). Storage devices 154, 156, 158,
160, 162 may be configured to provide various levels of performance
and/or high availability (e.g., via storage management application
21). For example, one or more of storage devices 154, 156, 158,
160, 162 (or any of the above-noted storage devices) may be
configured as a RAID 0 array, in which data is striped across
storage devices. By striping data across a plurality of storage
devices, improved performance may be realized. However, RAID 0
arrays may not provide a level of high availability. Accordingly,
one or more of storage devices 154, 156, 158, 160, 162 (or any of
the above-noted storage devices) may be configured as a RAID 1
array, in which data is mirrored between storage devices. By
mirroring data between storage devices, a level of high
availability may be achieved as multiple copies of the data may be
stored within storage devices 154, 156, 158, 160, 162.
[0055] While storage devices 154, 156, 158, 160, 162 are discussed
above as being configured in a RAID 0 or RAID 1 array, this is for
example purposes only and not intended to limit the present
disclosure, as other configurations are possible. For example,
storage devices 154, 156, 158, 160, 162 may be configured as a RAID
3, RAID 4, RAID 5 or RAID 6 array.
[0056] While in this particular example, target 150 is shown to
include five storage devices (e.g., storage devices 154, 156, 158,
160, 162), this is for example purposes only and not intended to
limit the present disclosure. For instance, the actual number of
storage devices may be increased or decreased depending upon, e.g.,
the level of redundancy/performance/capacity required.
[0057] In some implementations, one or more of storage devices 154,
156, 158, 160, 162 may be configured to store (e.g., via storage
management application 21) coded data, wherein such coded data may
allow for the regeneration of data lost/corrupted on one or more of
storage devices 154, 156, 158, 160, 162. Examples of such coded
data may include but are not limited to parity data and
Reed-Solomon data. Such coded data may be distributed across all of
storage devices 154, 156, 158, 160, 162 or may be stored within a
specific storage device.
[0058] The manner in which target 150 is implemented may vary
depending upon e.g., the level of redundancy/performance/capacity
required. For example, target 150 may be a RAID device in which
storage processor 152 is a RAID controller card and storage devices
154, 156, 158, 160, 162 are individual "hot-swappable" hard disk
drives. Another example of target 150 may be a RAID system,
examples of which may include but are not limited to an NAS (i.e.,
Network Attached Storage) device or a SAN (i.e., Storage Area
Network).
[0059] In some implementations, storage target 150 may execute all
or a portion of storage management application 21. The instruction
sets and subroutines of storage management application 21, which
may be stored on a storage device (e.g., storage device 164)
coupled to storage processor 152, may be executed by one or more
processors and one or more memory architectures included with
storage processor 152. Storage device 164 may include but is not
limited to any of the above-noted storage devices.
[0060] As discussed above, computer 12 may be configured as a SAN,
wherein storage processor 100 may be a dedicated computing system
and each of storage targets 102, 104, 106, 108, 110 may be a RAID
device. Accordingly, when storage processor 100 processes data
requests 116, 120, storage processor 100 (e.g., via storage
management application 21) may provide the appropriate
requests/content (e.g., write request 166, content 168 and read
request 170) to, e.g., storage target 150 (which is representative
of storage targets 102, 104, 106, 108 and/or 110).
[0061] In some implementations, during operation of storage
processor 152, content 168 to be written to target 150 may be
processed by storage processor 152 (e.g., via storage management
application 21). Storage processor 152 may include cache memory
system 172. Examples of cache memory system 172 may include but are
not limited to a volatile, solid-state, cache memory system (e.g.,
a dynamic RAM cache memory system) and/or a non-volatile,
solid-state, cache memory system (e.g., a flash-based, cache memory
system). During operation of storage processor 152, content 168 to
be written to target 150 may be received by storage processor 152
(e.g., via storage management application 21) and initially stored
(e.g., via storage management application 21) within front end
cache memory system 172.
[0062] Generally, a SAN Model may exist for a read I/O satisfied
from a storage system data cache, such as but not limited to the
VMAX.TM. data cache offered from Dell EMC.TM.. For instance, and
referring to the SAN Model Part 1 in FIG. 4 and the SAN Model part
2 in FIG. 5, storage management application 21 may receive an I/O
in the application layer (1) on a host server, which may be
funneled down through the block driver, protocol driver (e.g.,
SCSI) and HBA driver (e.g., Fibre channel) to allow the read
request to be sent via the SAN to a VMAX.TM. front end director
(2). Generally, the left side of FIG. 4 may be the host or server
(e.g., computer 12). The right side may be the storage array
software stack. The table in the middle may represent data and
metadata structures stored within the storage array, which
generally do not live in the server software stack. The I/O may be
recognized on the VMAX.TM. side by the HBA driver (3) and may then
be routed through a few layers including a protocol driver,
VMAX.TM. device driver, and into the I/O subsystem. At this point,
the I/O subsystem (e.g., via storage management application 21) may
perform a metadata subsystem query (4) (e.g., "Is this data in
cache?"). Metadata may be distributed on more than one server. This
metadata subsystem query may result in a remote memory request on
the server IB network to one of the other servers to access the
metadata content. After the server IB network internal request
completes and the results are returned to the I/O subsystem,
another request may be made of the cache subsystem to return the
requested data (5). Cache data may also be distributed on more than
one server. This cache subsystem request may result in a remote
memory read request on the server IB network to acquire the
requested data and place it in memory that the HBA driver may then
return to the host via a transfer over the SAN (6 and 7). Once the
data has been received by the HBA driver and the I/O has a
successful logical completion received from the VMAX.TM. side, the
data may then be returned to the application layer (8).
[0063] While the above system may be beneficial for some
implementations, for other implementations, it may be more
beneficial and/or cheaper to use "off-the-shelf" or "general
purpose" server CPUs for serving IOs into and out of local storage
devices. However, generally, software-defined storage systems and
hyper-converged infrastructure systems that may use off-the-shelf
server CPUs for serving IOs into and out of local storage devices
may have to re-implement all the data services at their level.
Typically, users cannot leverage trusted data services from storage
arrays in such SDS/HCI environments. To be clear, the above system
may also use off-the-shelf servers, but they generally do not have
a VMAX.TM.-aware software component running in the off-shelf-server
(e.g., computer 12).
[0064] Thus, as will be discussed below, off-the-shelf (OTS)
process 10 may enable the taking of traditional storage array
functionality, and moving part or whole I/O processing into an
off-the-shelf server CPU, while maintaining the storage array data
services. In some implementations, this may be accomplished by
having a VMAX.TM.-aware software running in computer 12, allowing
it to be part of internal fabric 114. As will be discussed below,
OTS process 10 may at least help, e.g., the improvement of an
existing storage technology, necessarily rooted in computer
technology in order to overcome an example and non-limiting problem
specifically arising in the realm of data storage. For instance,
OTS process 10 may use an efficient process to take traditional
storage array functionality and move part or whole I/O processing
into an off-the-shelf server CPU, while maintaining the storage
array data services.
The OTS Process
[0065] As discussed above and referring also at least to the
example implementations of FIGS. 6-9, OTS process 10 may receive
600, by a computing device, an I/O request. OTS process 10 may
identify 602 whether the I/O request is eligible for handling via a
first path without also requiring handling via a second path. If
the I/O request is eligible, OTS process 10 may process 604 the I/O
request via the first path on a host I/O stack without processing
the I/O request via the second path on a storage array I/O stack.
If the I/O request is ineligible, OTS process 10 may 606 the I/O
request via the first path on the host I/O stack and via the second
path on the storage array I/O stack.
[0066] In some implementations, OTS process 10 may receive 600, by
a computing device, an I/O request. For instance, and referring at
least to the example implementation of FIGS. 7-8, an example,
off-the-shelf (OTS) model (part 1) 700 and 800 (part 2) is shown.
In the example, assume for example purposes only that a user (e.g.,
user 46) would like to access data stored on the server metadata
and data store. Such an I/O request (e.g., I/O 15) may be generated
(e.g., via client computing device 38) and received 600 by OTS
process 10. In some implementations, client application 22 and user
46 may also be resident on computer 12, thus, the I/O request may
also be generated by computer 12 (via OTS process 10). In FIGS. 7
and 8, the left side may be the host or server (e.g., computer 12).
The right hand side may be the storage array software stack. The
table in the middle may represent data and metadata structures
stored within the storage array, and generally do not live in the
server software stack.
[0067] In some implementations, OTS process 10 may identify 602
whether the I/O request is eligible for handling via a first path
without also requiring handling via a second path. For instance, in
some implementations, I/O 15 may be initiated (received) at the
application layer and passed through the block device driver of the
host I/O stack (of the OTS host server) to a point where I/O 15 may
be identified 602 (e.g., recognized) as either being eligible for
"fast path handling" (e.g., handling via a first path, such as
example steps (1)-(4) in FIGS. 7-8, without also requiring handling
via a second path, such steps (3)-(7) in FIGS. 4-5). That is, the
need to involve the second path on a storage array I/O stack of the
storage array server may be completely obviated, thereby enabling
use of off-the-shelf or general purpose servers. Thus, in some
implementations, if the I/O request is eligible, OTS process 10 may
process 604 the I/O request via the first path on a host I/O stack
without processing the I/O request via the second path on a storage
array I/O stack, and if the I/O request is ineligible, OTS process
10 may 606 the I/O request via the first path on the host I/O stack
and via the second path on the storage array I/O stack.
[0068] In some implementations, the "fast path handling" shows how
OTS process 10 may process a host read command that is satisfied
out of the storage array cache. For instance, a quick metadata
access by OTS process 10 may help identify that the requested data
is present in the storage array cache and identify its location,
where OTS process 10 may then fetch the data from the storage array
cache and place it into the host memory, providing the application
layer with the requested data.
[0069] In some implementations, an eligible I/O request may include
one of a data read request and a data write request, and an
ineligible I/O request may include at least one of a control
command and an I/O request satisfying a predetermined condition.
For instance, in some implementations, only data read and write
requests may be identified 602 as being eligible for fast path
handling. Generally, control commands may be identified 602 as
ineligible for fast path handling, and thus potentially requiring
"slow path handling," such as the example shown in FIGS. 4-5. In
some implementations, the Server Device Handling layer in the host
I/O stack may have awareness (e.g., through coordination with the
storage array) of whether there are any "special conditions" that
may prevent fast path handling. For instance, if there is some
complicated state that requires intimate, instantaneous knowledge
of what is happening in the storage array, rather than trying to
keep the host I/O stack fully up to date with all of the necessary
information, OTS process 10 may determine it is easier for the host
layer to pass the command on to the storage array for normal/legacy
handling (i.e., "slow path handling").
[0070] In some implementations, the I/O request may be routed
(e.g., called from one layer into another layer) through
abbreviated versions of device and metadata subsystem handling by
OTS process 10. For instance, there may be different layers of
software functionality residing in the host I/O stack. In some
implementations, the host I/O stack changes may provide quick
responses to I/O requests that cover the majority of cases and
states. Thus, there may not be a need for the device and metadata
subsystem layers in the host I/O stack to deal with complicated
scenarios or system states. In some implementations, if OTS process
10 identifies the presence of such a complicated state/scenario, or
that some subtle handling may be needed, OTS process 10 may avoid
using the "fast path handling" and may instead send I/O 15 to the
storage array for "normal" handling (e.g., "slow path handling").
Thus, an example benefit to be had in I/O response time may come
from not loading the host I/O stack with lots of complicated state
handling, therefore enabling OTS process 10 to make a quick
go/no-go decision on the "fast path handling" viability, and either
proceed that way or offload the I/O to the slow path handling
route.
[0071] In some implementations, processing 604 the I/O request via
the first path on the host I/O stack without processing the I/O
request via the second path on the storage array I/O stack may
include processing 608 an optimistic query. For instance, the
components in the host I/O stack may not be sufficient to
participate in "full management" of the metadata subsystem (for
example) like the storage system server; however, those components
may have enough knowledge of that subsystem to satisfy optimistic
queries for "simple" (e.g., eligible) state handling. As noted
above, anything too "complicated" (e.g., ineligible) may result in
OTS process 10 passing I/O 15 to be processed 606 via the storage
array. An example of less than "full management" of the metadata
subsystem may include, e.g., read-only access to metadata
content.
[0072] Again, in the interest of being lightweight and fast, full
metadata subsystem access (including write/edit) capabilities may
require heavy (i.e. costly) operations, such as array-level
serialization semantics. If there are actions that the fast path
logic of OTS process 10 may undertake without needing to honor
these semantics, while also having the ability to detect
inconsistencies and silently retry if very small race conditions
are hit, such actions may be attempted. For example, OTS process 10
may assume that the abbreviated metadata subsystem has a
"good/optimistic" idea (but, not necessarily perfect or up-to-date
knowledge) of where to locate the metadata needed for I/O 15, and
if this good (but, not perfect) view of things is incorrect, OTS
process 10 may have sufficient redundancy to recognize that fact
and silently retry should something have changed right around the
time of the optimistic query.
[0073] Generally, having "enough knowledge" may refer to the "good,
but not necessarily perfect," view of the system. As an example,
assume that inside the storage array, any time it is desired to
move (e.g., page out, relocate, etc.) a piece of metadata, OTS
process 10 may require notification and positive acknowledgement
from all of the processors inside the storage array. However, in
the example host I/O stack model, OTS process 10 has a mechanism to
learn this information lazily and the picture of the system may be
substantially correct (e.g., 99% correct, but likely not 100%
correct).
[0074] In some implementations, and referring at least to the
example implementation of FIG. 9, an example storage system layout
900 with the storage array Server Device Handling Layer is shown in
more detail. The Server Device Handling Layer (or the driver)
brings storage array awareness to the server stack. In some
implementations, processing 604 the I/O request via the first path
(e.g., where P1 is the first path and P2 is the second path in FIG.
9) on the host I/O stack without processing the I/O request via the
second path on the storage array I/O stack may include generating
610 a metadata query based upon, at least in part, the I/O request.
For instance, the metadata query (shown via step (2)) may result in
an internal fabric request and the result of the query may be
called back to the device handler layer. For example, the generated
610 metadata query may be built out of the storage array Server
Device Handling Layer of the host I/O stack. I/O 15 may be
requesting data from a particular range of the logical storage
device that is presented to the application layer, and the metadata
query may be requesting the location/cache status of that data
within the storage array (e.g., "is this data in the array cache,
and if so, what cache address is it stored in?"), where the result
may include, e.g., a no/yes+address answer.
[0075] In some implementations, after realizing that the desired
data is in the cache, OTS process 10 (e.g., via the storage array
Server Device Handling Layer) may generate a request called through
an abbreviated cache-awareness layer (similar to the metadata-aware
layer, this component may satisfy optimistic queries but generally
cannot participate in full cache management operations such as,
e.g., allocation, recycling, LRU updates, etc.) that may generate
another fabric request to read the requested data from the cache,
as shown in step (3). In some implementations, the request may
include enough information to describe how to transfer data from
the storage array cache into the host memory, and may include such
information as, for example, source and destination fabric
addresses, information about how to ensure the self-consistency of
the data (e.g., if the data has an expected checksum, and if so
what is that value, etc.). The fabric request may include, e.g.,
source and destination fabric addresses, self-consistency
validation, etc.) and may be sent (via OTS process 10) to the
fabric and messaging driver of the host I/O stack so that the
fabric request may be turned into a physical request to read and
validate some memory that resides in the storage array (e.g., the
Server Metadata and Data Store).
[0076] In some implementations, OTS process 10 may return 612 a
completion status to an application layer of the host I/O stack
when processing 604 of the I/O request via the host I/O stack on
the first path without processing the I/O request via the second
path on the storage array I/O stack successfully completes. For
instance, upon the completion of the fabric operation, OTS process
10 may return 612 a completion status all the way up to the
application layer, as shown in step (4).
[0077] In some implementations, the I/O request may be processed
614 via the first path on the host I/O stack and via the second
path on the storage array I/O stack when processing 604 of the I/O
request via the host I/O stack on the first path without processing
the I/O request via the second path on the storage array I/O stack
fails. For instance, should there be any sort of I/O failure in the
fast path processing 604 (e.g., processing 604 of the I/O request
via the host I/O stack on the first path without processing the I/O
request via the second path on the storage array I/O stack) OTS
process 10 may retry the processing of I/O 15 by, e.g., using the
slow path (e.g., processing 606 via the first path on the host I/O
stack and via the second path on the storage array I/O stack).
[0078] Thus, in some implementations, OTS process 10 may bring
awareness of the storage array internal semantics into the host I/O
stack server as a "driver" (e.g., the Server Device Handling
Layer), e.g., in the operating system. OTS process 10 may not have
the full frontend functionality within the storage array; however,
OTS process 10 may encapsulate most of the I/O processing
capabilities, such as where data resides in the data persistence
layers (e.g., in global memory or in storage media). In some
implementations, OTS process 10 may enable off-the-shelf computer
elements to reside directly on the array backplane/fabric. This may
enable low latency and high bandwidth access to the data. In some
implementations, OTS process 10 may include enablement to cache the
data (read only or read/write) locally on the persistent media in
servers (e.g., computer 12). This may extend array level cache
coherence and clustering capabilities to the servers, and may help
bring array based data closer to processing units (e.g.,
CPU/GPU/TPU) in the servers for applications that may require high
performance/low latency operations, such as machine learning,
artificial intelligence, OLTP and DSS/DWH RDMBs, no-sql DB s,
etc.
[0079] The terminology used herein is for the purpose of describing
particular implementations only and is not intended to be limiting
of the disclosure. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. As used herein, the language
"at least one of A, B, and C" (and the like) should be interpreted
as covering only A, only B, only C, or any combination of the
three, unless the context clearly indicates otherwise. It will be
further understood that the terms "comprises" and/or "comprising,"
when used in this specification, specify the presence of stated
features, integers, steps (not necessarily in a particular order),
operations, elements, and/or components, but do not preclude the
presence or addition of one or more other features, integers, steps
(not necessarily in a particular order), operations, elements,
components, and/or groups thereof.
[0080] The corresponding structures, materials, acts, and
equivalents (e.g., of all means or step plus function elements)
that may be in the claims below are intended to include any
structure, material, or act for performing the function in
combination with other claimed elements as specifically claimed.
The description of the present disclosure has been presented for
purposes of illustration and description, but is not intended to be
exhaustive or limited to the disclosure in the form disclosed. Many
modifications, variations, substitutions, and any combinations
thereof will be apparent to those of ordinary skill in the art
without departing from the scope and spirit of the disclosure. The
implementation(s) were chosen and described in order to explain the
principles of the disclosure and the practical application, and to
enable others of ordinary skill in the art to understand the
disclosure for various implementation(s) with various modifications
and/or any combinations of implementation(s) as are suited to the
particular use contemplated.
[0081] Having thus described the disclosure of the present
application in detail and by reference to implementation(s)
thereof, it will be apparent that modifications, variations, and
any combinations of implementation(s) (including any modifications,
variations, substitutions, and combinations thereof) are possible
without departing from the scope of the disclosure defined in the
appended claims.
* * * * *